Bi₂Te₃-based alloys, generally prepared by traditional zone melting or hot-pressing, have been used in commercial applications for decades. However, the zone melting method is time-consuming and usually accompanied by poor thermoelectric performance, while the hot-pressing sintering needs complex and high-cost equipment. In this work, high-performance p-type Bi_0.4Sb_1.6Te₃ alloy is prepared by cold pressing the ball milled Bi_0.4Sb_1.6Te₃ powder followed by vacuum annealing, which is more suitable for large-scale promoting with cost saving. Owing to the low lattice thermal conductivity brought by fine grains, a peak ZT value of ∼1.15 at 50 °C and an average ZT value of ∼0.84 within 30–250 °C are realized, which are comparable with the excellent performance achieved by zone melting and hot-pressing, and are even better than that of the optimized cold-pressed sample. More importantly, the thermoelectric performance here shows good repeatability from batch to batch. Our work makes the widespread application of Bi_0.4Sb_1.6Te₃ alloy in thermoelectric power generation and refrigeration an important step forward.

Bi ₂ Te ₃基合金通常通过传统区域熔化或热压制备，已在商业应用中使用了数十年。但区熔法耗时长，热电性能差，而热压烧结需要复杂且成本高的设备。本工作采用球磨后的Bi _0.4 Sb _1.6 Te ₃粉末冷压后真空退火制备高性能p型Bi _0.4 Sb _1.6 Te ₃合金，更适合大规模推广，节约成本。由于细晶粒带来的低晶格热导率，峰值ZT在 50°C 下达到 ~1.15 的值，在 30-250°C 内实现了 ~0.84的平均ZT值，这与区域熔炼和热压实现的优异性能相当，甚至优于优化的冷压样品。更重要的是，这里的热电性能在批次之间显示出良好的可重复性。我们的工作使Bi _0.4 Sb _1.6 Te ₃合金在热电发电和制冷方面的广泛应用向前迈出了重要的一步。